The training of drivers of motor vehicles that follow routes, such as buses, has traditionally involved a trainer giving instructions to a driver as a route is being followed. More recently, video technology has been used to provide classroom training. Typically a route is filmed while an instructor is recorded as he gives guidance on driving technique that is appropriate to particular parts of the route and points out significant features on the route, e.g. accident black spots, road hazards, interchanges, etc. The moving picture of the route and accompanying sound track are then played back to trainees in the classroom often by means of computer based playback apparatus. General purpose computer platforms, such as Personal Computers, are often used for the purpose.
Typically, the moving picture track and the sound track are recorded together and then stored in a combined manner as video and sound data streams on an appropriate storage medium, such as on magnetic tape or in a hard disc drive. Thus, the co-relation of the moving picture track and sound track is maintained such that on play back of the data streams the instructor's commentary is properly synchronized with the moving picture of the route.
The present applicant has appreciated that such an approach has shortcomings when routes are liable to change over time. For example, a part of the route may change necessitating a change to the moving picture track. A known approach to accommodating such a change is to re-record the whole route. However, this approach can be time consuming, laborious and expensive where only part of a whole route has changed.
An alternative known approach is to re-record only the changed part of the route to produce a new portion of track. A video editing suite is then used to incorporate the new portion of track in the existing moving picture track for the whole route and produce a modified video data stream for storage combined with the sound data stream on the chosen storage medium. This approach has the advantage of saving on time and labour at the re-recording stage. However, the burden is shifted to the video editing stage, which can be laborious and normally requires skilled operation to ensure proper co-relation of the new portion of track with the existing track.
A further example of the shortcomings of the conventional approaches is where the route has changed in the sense of requiring a further track of information of a different kind, e.g. motor vehicle speed along the route. According to the first conventional approach the entire route would need to be re-filmed along with re-recordal of the sound track and recordal of the further track of information. According to the second conventional approach the further track of information could be recorded alone. However, use of an editing suite would be required to properly co-relate the further track of information with the existing tracks of information.